Coupling electrooxidation and Oxone for degradation of 2,4-Dichlorophenoxyacetic acid (2,4-D) from aqueous solutions

Electrodegradation of 2,4-dichlorophenoxyacetic acid herbicide from aqueous solution using three-dimensional electrode reactor with G/β-PbO2anode: Taguchi optimization and degradation mechanism determination

“…In the present study, Na 2 SO 4 was selected as an SE. The use of the Na 2 SO 4 , as an auxiliary electrolyte, to boost the 38 which it conrms the results of the present study. The optimum amount of Na 2 SO 4 (used as supporting electrolyte, SE) was determined using the appropriate applied voltage.…”

“…Reviewing the previous studies illustrated that several type of methods including electrochemical, electrochemical coagulation, coupled Fenton and biological oxidation and oxidation processes have evolved for the degradation of 2,4-D herbicide. 14,38,[42][43][44][45][46][47] Table 7, compares these processes from the viewpoint of initial pH, electrolysis time, initial 2,4-D herbicide concentration, current density, electrode type, degradation efficiency and COD removal with the prepared electrode in this research. According to Table 7, our data in the most cases are superior to previously reported data.…”

Parameter optimization and degradation mechanism for electrocatalytic degradation of 2,4-diclorophenoxyacetic acid (2,4-D) herbicide by lead dioxide electrodes

“…Jaafarzadeh et al (2018) observed that decreasing the pH and increasing the electrolysis time are led to improve the 2,4-D removal efficiency; it is in line with the present study. 41 In the present study, increasing the 2.4-D degradation in acidic pH can be attributed to the higher efficiency of the hydroxyl radical production in acidic pH values and production of some ions such as Cl, Cl 2 and HOCl that have higher efficiency at acidic pH values. 45,46 The effect of current density on the degradation of 2,4-D is presented in Fig.…”

“…The greater hydroxyl radical generation at the higher current density may be the reason for this event; so that, the herbicide degradation efficiency using SS316/b-PbO 2 electrodes (from 36.0 to 60.4%), Pb/b-PbO 2 (from 52.6 to 75.6%) and G/b-PbO 2 (68.1 to 89.8%) is developed by increasing the current density from 1 mA cm À2 to 5 mA cm À2 at the same conditions (pH ¼ 3 and time ¼ 80 min), which is consistent with the study conducted by Jaafarzadeh et al (2018). 41 In their study, the results showed that increasing the current density increases the removal efficiency of herbicide; so that, increasing the current from 10 mA cm À2 to 40 mA cm À2 is led to enhance the removal efficiency from 52% to 82%. 41 In the study conducted by Yahiaoui et al (2013), it was observed that the tetracycline (TC) removal efficiency is developed by increasing the current density; so that, the removal efficiency increased from 33.5 to 77.7% by increasing the current density from 2.5 to 25 mA cm À2 , 47 which is in accordance with the present study.…”

“…41 In their study, the results showed that increasing the current density increases the removal efficiency of herbicide; so that, increasing the current from 10 mA cm À2 to 40 mA cm À2 is led to enhance the removal efficiency from 52% to 82%. 41 In the study conducted by Yahiaoui et al (2013), it was observed that the tetracycline (TC) removal efficiency is developed by increasing the current density; so that, the removal efficiency increased from 33.5 to 77.7% by increasing the current density from 2.5 to 25 mA cm À2 , 47 which is in accordance with the present study. As discussed before, this effect should be related to increasing the production of electrogenerated OHc radicals from the water discharge by increasing current density.…”